View Full Version : Polyiso foam - got questions

12-13-2011, 07:12 PM
Ok... I watched Larry's DVD on How to Foam Carve Your Haunted House. I have been tossing around for awhile about wanting to do some spray foam caves and tunnels. I decided to dial back the spray foam and to incorporate some foam board to do bricks and rock outcroppings.

My question is how good is polyisocyanurate foam?? Anyone with experience? I know what the white beaded foam and what the pink or blue foam does. What will the polyiso foam do if you want to create brick mortar lines with a rasp or weedeat the thing. I've seen a video where it is cut on a large bandsaw with an abrasive wire for the blade. Anyone tried a hotwire cutter? The melting point for the white/pink/blue foam is around 160f. This poly foam is about 300f. This stuff is also pretty rigid and in some cases considered a structural product. I have about 1300-1400 cubic feet in thick sheets available to me for a ridiculously cheap amount. Just looking for input before I commit myself.

Jim Warfield
12-13-2011, 10:15 PM
Running a haunt, to have ones self commited. But that would be too easy. Life is about suffering and experiencing our truly deserved pains and not wimping out, right?

12-13-2011, 11:46 PM
I have been scouring the net for a used CNC router. Dreaming of all the tombstones that I could make.... What I have found out is that this stuff is machinable, sandable, drill holes in it, etc. If it gets hot it will turn brown, but wont melt. Whereas other foams will melt and run all over the place. Probably not far off from being like a piece of balsa wood.

Allen H
12-13-2011, 11:48 PM
What density is it? that will tell you how workable it is. density is determined by how many pounds does 1 cubic foot weigh? EPS foam is normally 1-2lb foam. Over 12lb foam is almost like working with wood- so density is important.
Allen H

12-14-2011, 01:04 AM
I'm not sure the density right off hand. I'll find that out 1st thing in the morning for sure.